I've been doing bunch of carbon fiber work over the last few months, stuff like this for example:



I realized it could really be complemented well with a nice carbon fiber hood or carbon fiber hood vents. I know that a lot of the CF hoods out there have poor fitment and many are about the same weight as the stock aluminum one (poor quality I suppose), so I decided to design my own drop in hood vents.
I wanted something that has a bit of the British sports car feel as those designs seem generally timeless. Something along the lines of these:

Aston Martin:



DBS Superleggera:





And one of my persona favorite racecars, the Bentley GT3
I absolutely love the massive vents on this one:






So I started working on a design and this is where I'm at right now and I welcome any suggestions:






Now I'm not sure about just how much curve looks best. I do like the super curved design of the Bentley, but it may look a bit wonky on the G. Suggestions welcome:

Nearly flat:


More curve:


Super Curved:



It's hard to visualize with a flat picture (no full 3d drawing of the car...yet), but I do like the look of the high curve profile:






I do have the hood shape figured out and at least this part is done, now I need to finalized the 3D shape of the vent and get to the best part 3d printing a prototype and cutting some holes




I welcome suggestions before I start cutting and make things final.

 

Your favorite Bentley race car has those specific vents because of the uniquely mounted radiator system. This would be more form over function, I suppose. Would also let in quite a lot of snow / rain, right? I’m interested to see how it will work out, it’s a lot and most aftermarket are the same.

 

Yup, the cooling system on that bentley is full on racecar, the depth of those ducts only really become apparent when you see the hood from the side:



No way can I replicate that, but I can get some of the style points...with a bit of the functionality. Not gonna lie, last year when I went to a track day in June/July I did have cooling issues.

The same cooling system design language is applied to the Aston Martin Vantage GT3. Just look at those ducts!







As for rain and snow ingress....I did give this some thought. Although I likely won't have time to get this part done before track season kicks in, eventually I think I will stick some ducting/trays underneath the hood and pitch it towards the radiator so that if any rain does get in it doesn't end up on top of the motor or any electronics that shouldn't get wet.
I suspect few people remember this car:
http://www.speedhunters.com/2012/03/...skyline_gt_r/#
but it had a very interesting addition under the hood:


This was used to feed the ITBs, but that kind of under hood attachment idea can obviously be applied to any kind of air routing. The really tricky bit will be under hood clearance...I am a bit worried about that and will only get a clear picture of it once I cut some holes and 3d print the first prototype. I may also need to get rid of the stock airbox and reroute the intake if it gets in the way or too close to the hood ducts. Additionally I know for sure I am ripping out most of the factory hood bracing on the bottom of the hood, so that will immediately add some clearance.

Suggestions as always welcome.

 

I’m always excited to see “because race car” stuff, and this looks like it will be totally functional. I’m glad you are doing something different and can’t wait Tom see it prototyped.

I love that 3d printing is so much more accessible these days. I printed some brake ducts for motorcycles a couple days back for the total cost of electricity and media of about $3 ha.

 

First prototype 3D printed and immediately a bunch of challenges and ideas pop up.

I like the size and shape of the vent



Without cutting it into the hood it does seem to fit nicely on top of it.



However, it's immediately clear that I will need to remove the airbox and duct the intake through the front radiator support and put a new filter behind the grill. Not a big deal and kind of expected, but still. Obviously a bit more engineering will be required to make this properly functional.



Same goes for the passanger side, where the overflow bottle will obviously need to be relocated or replaced with a much smaller unit. Likewise the power steering canister will need to be relocated to the battery compartment, which luckily for me is empty since I placed the battery in the trunk a while ago. Again, not too difficult, but more engineering needed.




I think I need to cut the holes in the hood next, can't really proceed much further until I do that

 

Couldn't agree more. When I first started doing the carbon bits I was messing around with hot wire cutting foam and filler and lots of sanding while trying to make the right shapes by hand....man, was that a lot of time and effort. Now I can go from idea, to multiple prototype revisions, to making a mold within a few days. 3D printing is just an amazing tool for rapid component development.

 

New intake ducting in development, first need to connect to the mass flow sensor (easy; 4 point flange), then get the angles right to bring it up to the inside of the radiator support.



The question that comes up thought is how are people getting around the AC lines behind the radiator support. I used a scotch tape that's about 90mm (~3.5") in diameter and it def gets in the way of the AC lines, so I either need to come up with an oval or warped shape to get through and around or maybe the AC core can be shifted over to the passenger side. How are people routing 90mm intake pipes through this section???

 

More progress:

3D printed intake tube prototype now has a shape that lines up pretty well and no longer gets in the way of the hood vent, unlike the OEM intake box, which got completely in the way. The transition through the radiator support needs to be figured out next.

3D printed only half of it to save on PLA. Final version will be printed in ABS, which should survive the under hood temps.




On the other side I had to do something about the coolant overflow canister, so I order a small one I found on ebay made for a Suzuki.

This has to go:



New overflow canister will go into the battery space:






That should give me enough clearance to install the hood vent on the passenger side.

Progress...

 

Some progress. As mentioned before, before the hood vents can go in I have to clear the area where the vents will pick up air. This means getting rid of the airbox and getting rid of the coolant bottle and the power steering reservoir on the passenger side.
I made some progress on both ends. On the driver side I now have a hole through the radiator support and I cut out some of the headlight support bracket out to make more space for the new intake duct to go through...its just a tight area. The hole I made in the headlight bucket I filled back up with a new shape with some carbon fiber with more clearance now.

New intake path, now somewhat allowing more space to go around the A/C condenser lines:


I had to cut out some of the headlight bucket to make more space, but filled the hole back in with carbon, just with more clearance now:




Unfortunately I still don't have enough space to pull through a clean and perfectly round 3.5" pipe, so I will have no choice but to come up with some slightly odd shape to get through here....the AC condenser lines are killing me.


Passenger side:
I now have a bracket for the relocation of the coolant overflow bottle and power steering fluid reservoir. Initial partial print and test fit looks great:





Entire bracket will be able to support my battery relocation cable, coolant canister, and power steering reservoir:



While at it I also started reworking my power steering cooler (the old one looked awful), so found this $25 one on amazon (per recommendation from some folks over on my350z) and it fits well. Just need to clear coat some new carbon brackets.


and yes my oil cooler line needs to be re-worked. I'm waiting on a new AN fitting to make that look well.

Anyways, progress made...this is taking a bit of effort since things under the hood need to be moved around to make these custom vents fit the way I want them.

 

Wow! That looks good. I Really need to look into an oil cooler as my Ps one also looks cooked. I think an aftermarket oil cooler would be a good choice for the engine oil. Afaik the manual trans cooler is different than auto (if any at all). I should have engine out this weekend.

 

The cooler looks good in person, hopefully doesn't spring any leaks once pressurized. This is the one I bought. On sale now for ~$24:

The oil looker I have is the Z1 kit with a Setrab core, I just changed the mounting of it so its vertical (rotated 90degrees). Fits better and technically its the correct way to mount (liquid in on bottom, out on top so it purges air).

While I have the bumper off I did some work to finish up my bumper inlet ducting. All of this should help improve cooling along with a new radiator and the hood ducts.




Good luck on the engine pull, I'm following along on the other thread

 

Insane price on that!

 

ok, some nice progress. First print of the complete coolant and power steering bottles in ABS plastic turned out well, but will redo in black for a more OEM look and make some minor changes. Almost there with the canister relocations!

 

Well done so far! Really nice to see some new things being done on the V35 platform. I see in your pictures you’ve made carbon replacements for the aluminum front crash bar. Is there a significant weight savings with that?
As for the vents I really like what your doing and think they would really nice on a car with other similarly aggressive mods (aero etc.)
Personally I am more of a fan of the earlier Aston Martin hood vents that are a little more subtle. There was a carbon hood available at one time that had them and I always thought they looked great.

If there was a vent insert like this rather than the whole hood, I would be very interested. From a functional standpoint they would be very useful to those with headers as many well know they increase engine bay heat quite a bit, even with wrap.
keep up the great work!

 

Thanks for the kind words
I had to go back to my notes regarding the crash bar since that goes back to 2019. The carbon fiber bar I made weights 5.2lbs, the OEM aluminum one was 12.7lbs. I did my best measurement of torsional rigidity when I made it and it seems to be about the same as the aluminum, maybe 10% less. However I expect its much better in terms of tensile strength across the two mounting locations since I put in multiple layers of unidirectional fibers running across and really I expect that's where the strength really counts. Weight savings weren't that substantial mostly because I never replaced the crash bar support brackets (2 of them) and those are made of steel unlike the aluminum crash bar and are stupid heavy for a pair of brackets. More than anything the crash bar was a learning experience in making structural carbon parts.



The earlier Aston designs were indeed also very nice as was that carbon hood you have a pic of. The v8 vantage and v12 vantage had absolutely great hood vent designs:



You can still buy these btw and they aren't really that expensive:
https://www.carbonfiberracing.com/st...ood_Vents.html

I've considered getting these and making them fit to the OEM hood, but figured if I have the ability to make something of my own design....well, might as well give it a try.